In such fastenings, which are sometimes referred to as snap fastenings and are used for example for the closing of belts or the like, there is a danger that the fastening may open in response to unintended but severe bending stresses in a particular direction, for example as a result of lateral pressure.
It is an object of the present invention to avoid this drawback and to provide a fastening which can only be opened in a predetermined and approved direction. To this end this invention consists in the improvement wherein each row of pins is mounted on a non-elastically deformable reinforcement connected to the parent carrier part in question with the reinforcements on each carrier disposed substantially at right angles to the longitudinal axis of the carrier, whereby the fastening can be separated in the direction of this axis only.
In accordance with a further feature of the invention the carrier part may be a plate, advantageously of rubber or the like with a fabric insert, and the pins on each plate are disposed with the heads of each row projecting from one side of the plate and rigidly connected to a reinforcement of strip form arranged at the other side of the plate and lying at right angles to the said direction of separation.
In a useful arrangement the coupling pins are made of metal and are connected by riveting or soldering to the reinforcing strips, which are also of metal.
In another arrangement each carrier is a plate of material of high elasticity and the coupling pins of each row and the corresponding reinforcement are made as a unit of strip form of material of lesser elasticity, this strip form unit being connected to the plate with the length of the strip form unit disposed at right angles to the said direction of separation.
A viable series production is catered for if the plate is of a thermoplastically moldable material, for example rubber, and the strip form unit is preformed from plastics material of less elasticity and is connected to the plate during thermoplastic molding of the latter.
In the case of belts or the like which are to be fastened together at their ends in the usual way, in accordance with a further feature of the invention at least two adjacent reinforcements disposed at one end of each carrier are firmly connected together by at least one bridge piece. This provides the fastening with an end closure which is very resistant to opening in an oblique or other unwanted direction.
A further object of the invention is to provide a very simple but nevertheless reliable arrangement for closing and opening the fastening. To this end use may be made of an operating member substantially S-form which is movable in a prescribed direction for opening and closing the two carriers of the fastening, said operating S-member having a central limb which, when the operating member is assembled on the fastening, extends between the carriers at right angles to the direction of separation, and is adapted to effect the separation of the pins of the respective carriers when pulled in one direction, and having two end limbs which also extend at right angles to the direction of separation and are adapted to bear on the outer sides of the carriers and to effect the closing of the fastening.
In a preferred form of this operating member the central limb is pivotally connected to a handgrip. This will help the unfastening and fastening operation in the case of wide fastenings. Moreover the handgrip can be made of various shapes suited to the appearance of the garment or belt.
A very simple method of limiting the closing and opening movement of this member is provided by a feature of the invention in which at least one of the carriers has an end abutment to cooperate with the corresponding end limb of the operating member and retain the latter in association with the fastening, the part of the end abutment facing the end limb of the operating member having a security notch to receive this limb.
A useful expedient is achieved where the inner side of each carrier is left free of coupling pins in the zone of the end abutment. This means that the ends of the two carrier parts can lie flat against one another in a closed position despite the presence of an S-member between them.
All the parts of the S-member can be made of circular cross section and of the same diameter. In this case the S-member can be made from metal wire or consist of a thermoplastic molding.